exSID USB

Assembly Guide

Disclaimer

The information and methods described herein are provided “AS-IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED. Use the concepts, examples and information at your own risk. There may be errors and inaccuracies, that could be damaging to your devices. Proceed with caution, and although it is highly unlikely that accidents will happen because of following advice or procedures described in this document, the author does not take any responsibility for any damage claimed to be caused by doing so.

Introduction

This assembly guide assumes some basic soldering skills on the part of the reader. It is a step-by-step explanation of how to properly assemble the exSID USB revision C.

Note: This kit is not suited for DIY beginners. While designed to be easy to assemble, it will require prior experience assembling DIY kits.

The underlying idea is to start with the thinnest components first (those with the lowest “elevation” on the PCB) and move toward the thickest/tallest components.

Step 1

The first step is familiarizing yourself with the PCB, show here in HASL finish.

Step 2

If you start from a bare PCB, the SMDs are the first devices that must be soldered: IC1 and Q1.

These parts have polarity: the silkscreen for IC1 has a dot that must be aligned with the beveled dot on the chip. Q1 has an odd number of pins, making mis-orientation impossible.

As mentioned in the layout comments section, they will require solid soldering skills. HASL-finish PCBs certainly help there.

Step 3

Next, solder the mini-USB connector.

Mini-USB

The pins of the mini-USB connector will barely protrude when the connector is fully seated on the PCB. This is normal. After making sure the connector is firmly stead, use a fine (≤1mm) solder tip to solder the data pins first. Then use a larger solder tip to pour a generous amount of solder on the shield pins. In the end, it should look like this:

Step 4

Next, solder the horizontal resistors: R1, R2, R3, R4, R5 These components do not have polarity (they can be soldered in any orientation), however the designated values must be respected:

Note: C10 and C11 (located between the two SIDs) only appear later in the pictures but they really need to be soldered now.

Step 6

Continue with the film capacitors (the rectangular ones), C9, C12, C13, C14. Their value will be specified plainly on the casing (e.g. 1nJ100 means 1nF, 100V, 5%). They are not polarized.

Step 7

Now is a good time to solder the vertically-mounted resistors, R6, R7, R8, R9, R10, R11, R12. They can be soldered in any orientation, but it’s best to place the component on the designated spot (the circle on the silkscreen) as this is the only placement that has been validated for physical clearance with other components.

100Ω is color-coded as Brown, Black, Brown, Gold

1kΩ is color-coded as Brown, Black, Red, Gold

10kΩ is color-coded as Brown, Black, Orange, Gold

Step 8

Next up are the 2N3904 transistors T1, T2. These components are polarized and must be mounted in the proper orientation. The flat side of the transistor is reflected on the PCB silkscreen: they must be aligned. The middle pin will typically have to be slightly bent backwards before insertion to fit the PCB footprint.

Step 9

Up next are the electrolytic capacitors C4, C17, C18. These devices are also polarized. The devices have their negative pin marked on the package, usually by a distinctive band, as can be seen on this picture. That pin must be inserted on the opposite side of the solder pad marked with a tiny + on the PCB, which obviously denotes the positive pin place. All 3 capacitors have the same orientation on the PCB. Their value is printed on the package.

Step 10

In this step we’ll solder the voltage converters V1, V2. These devices are polarized, and while they look identical, they are different devices. Make sure to use the correct one in each place. The silkscreen on the PCB clearly hints the correct orientation of the devices: pins and markings towards to outer edge of the PCB.

V1: TME0512S

V2: TME0509S

Step 11

The device is now almost ready. This step shows the addition of the IC sockets, as well as the output jack.

Step 12

In this step we add the vertically-mounted choke L1, right next to the mini-USB connector. This device is not polarized.
Finally we add the two LEDs, LED1, LED2. These devices are polarized. They normally have a flat side and/or a shorter leg that must be aligned with the flat side drawn on the PCB silkscreen, toward the edge of the PCB.

Step 13

It is now time to insert the ICs IC2, IC3, IC4in the correct orientation (mind the notch on the IC that must be matched with the notch on the PCB silkscreen: all 3 ICs have the same orientation), and this completes the assembly of exSID USB!

Note: If you plan to do some voltage measurements before inserting the SIDs in their sockets, please note that the regulators cannot regulate properly without a load. Thus it is normal to read a higher voltage than expected for the +9V and +12V rails. As soon as any load is connected (the SID chips or a simple 1k to 10k resistor to ground) the voltage will settle to the correct value.

Case assembly

If you use the laser-cut acrylic case I designed, the case elements come with a white plastic protection layer that must be peeled off before assembly. The faces covered with that protection layer are the inside of the box. Assemble all but the two sides which have a hole for the USB and jack connectors: insert the exSID inside the case and then close the remaining two sides.

The case is a lego-style system where each side snaps together with the adjacent one. Be gentle during assembly as acrylic is brittle and does not tolerate well excessive force. The snug fit of the jagged edges provides enough strength to not require glue.

An extra pair of grooves has been added to the bottom side of the case (see below) to facilitate re-opening if that ever proves necessary (insert a flat screw driver in the groove and exert a very gentle outward pressure on the adjacent side).

Note: The case “reopening” feature is really there “just in case”. It is highly preferable to confirm the device is operating correctly before closing the case!